1.\" $NetBSD: echo.1,v 1.13 2003/08/07 09:05:40 agc Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Kenneth Almquist. 8.\" Copyright 1989 by Kenneth Almquist 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)echo.1 8.1 (Berkeley) 5/31/93 35.\" 36.Dd May 31, 1993 37.Dt ECHO 1 38.Os 39.Sh NAME 40.Nm echo 41.Nd produce message in a shell script 42.Sh SYNOPSIS 43.Nm 44.Op Fl n | Fl e 45.Ar args ... 46.Sh DESCRIPTION 47.Nm 48prints its arguments on the standard output, separated by spaces. 49Unless the 50.Fl n 51option is present, a newline is output following the arguments. 52The 53.Fl e 54option causes 55.Nm 56to treat the escape sequences specially, as described in the following 57paragraph. 58The 59.Fl e 60option is the default, and is provided solely for compatibility with 61other systems. 62Only one of the options 63.Fl n 64and 65.Fl e 66may be given. 67.Pp 68If any of the following sequences of characters is encountered during 69output, the sequence is not output. Instead, the specified action is 70performed: 71.Bl -tag -width indent 72.It Li \eb 73A backspace character is output. 74.It Li \ec 75Subsequent output is suppressed. This is normally used at the end of the 76last argument to suppress the trailing newline that 77.Nm 78would otherwise output. 79.It Li \ef 80Output a form feed. 81.It Li \en 82Output a newline character. 83.It Li \er 84Output a carriage return. 85.It Li \et 86Output a (horizontal) tab character. 87.It Li \ev 88Output a vertical tab. 89.It Li \e0 Ns Ar digits 90Output the character whose value is given by zero to three digits. 91If there are zero digits, a nul character is output. 92.It Li \e\e 93Output a backslash. 94.El 95.Sh HINTS 96Remember that backslash is special to the shell and needs to be escaped. 97To output a message to standard error, say 98.Pp 99.D1 echo message \*[Gt]\*[Am]2 100.Sh BUGS 101The octal character escape mechanism 102.Pq Li \e0 Ns Ar digits 103differs from the 104C language mechanism. 105.Pp 106There is no way to force 107.Nm 108to treat its arguments literally, rather than interpreting them as 109options and escape sequences. 110